The specific ion effect on emulsions, foam and gels of a seed protein concentrate

Protein concentrate was prepared from the seeds of jack bean (Canavalia ensiformis) and the influences of selected Hofmeister salts on some functional properties of the protein concentrate were investigated. The results indicate that kosmotropic salts (Na2SO4, NaCl, NaBr) had improved water absorption capacities over the chaotropic salts (NaI, NaClO4, NaSCN) and generally, the reduction in water absorption capacity followed the Hofmeister trend: Na2SO4 > NaCl > NaBr > NaI > NaClO4 > NaSCN. However, the reverse was observed for the foaming and emulsification properties. The least gelation concentration (LGC) was used as the index of gelation properties and the results showed that LGC were higher in kosmotropic salts than in chaotropic salts. Generally, increases in salt concentration reduced the water absorption capacity, the surfactant properties as well as the gelation property. The findings would provide insight into the understanding of the structure property relations of the protein concentrate. (author)